Background

My research group study the behaviour, reproduction and ecology of birds. We are especially interested in mating systems, sexual selection and sex roles during reproduction. Recently, we have been working on the influence of early learning for mating behaviour by adopting a method of heterospecific cross-fostering of birds in the wild.

The model species used have mainly been small passerine birds, namely the pied flycatcher Ficedula hypoleuca, the great tit Parus major, and the blue tit P. caeruleus because these species are common and accept to breed in our nestboxes. The field work is carried out in study sites in woodlands near the University. We also take blood sample for analyses of paternity and hormone levels.

Climate change will affect the population dynamics of many species, yet the consequences for the long-term persistence of populations are poorly understood. A major reason for this is that density-dependent feedback effects caused by fluctuations in population size are considered independent of stochastic variation in the environment. We show that an interplay between winter temperature and population density can influence the persistence of a small passerine population under global warming. Although warmer winters favor an increased mean population size, density-dependent feedback can cause the local population to be less buffered against occasional poor environmental conditions (cold winters). This shows that it is essential to go beyond the population size and explore climate effects on the full dynamics to elaborate targeted management actions.